We have investigated the charge-spin-ordering transition in (formula presented) by measurements of Raman and optical conductivity spectra. The checkerboard-type charge ordering below (formula presented) can be probed by activated phonon (formula presented) and (formula presented) and two-magnon (formula presented) modes in the infrared and Raman spectra as well as by formation of pseudogaps in the optical conductivity spectra. Besides, another (formula presented) Raman mode emerges below 150 K together with reduction of the optical gap, which can be attributed to another ordering process, i.e., the stripe formation.
|ジャーナル||Physical Review B - Condensed Matter and Materials Physics|
|出版ステータス||Published - 2003 1月 1|
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